A wire harness is constructed from numerous electrical wires, contacts, and the like. The contacts may be, for example, connected to the electrical wires of the wire harnesses and then arranged in a housing of an electrical connector. A locking arm may be disposed in the housing to secure the contacts and to prevent the contacts from slipping out of the housing.
In order to prevent erroneous wiring of the wire harness and in order to prevent faulty connections between the contacts and the electrical wires, an electrical continuity check of the electrical connector is required. One example of an electrical continuity testing method is shown in FIGS. 11A, 11B, and 11C and is further illustrated in Japanese Patent Application Kokai No. 2000-182743. FIGS. 11A, 11B and 11C, show an electrical connector 101 having an insulating housing 110. A plurality of contact accommodating passageways 111 are formed in two rows (upper and lower) in the housing 110. A plurality of contacts 120 is accommodated in the contact accommodating passageways 111. A rear holder 130 has locking arms 131 for securing the contacts 120.
Each of the contacts 120 includes a securing member 121 that is secured to the rear holder 130, a male contact member 122 that extends forward (toward the left in FIG. 11A) from the securing member 121, and an electrical wire connecting member 123 that extends rearward from the securing member 121. The electrical wire connecting member 123 is connected to an electrical wire 140 of a wire harness (not shown) by crimping. The rear holder 130 is inserted from a rear side of the housing 110 and is locked to the housing 110 in either a temporary locking position shown in FIG. 11A or a main locking position shown in FIG. 11C. The temporary locking position allows insertion of the contacts 120 into the housing 110, and the main locking position fully secures the contacts 120 in the housing 110.
A first opening 114 is formed in a top wall 112 of the housing 110 and communicates with the contact accommodating passageways 111 of the upper row. A second opening 115 is formed in a bottom wall 113 of the housing 110 and communicates with the contact accommodating passageways 111 of the lower row. The first and second openings 114, 115 are formed in positions that allow contacts 153, 154 of electrical continuity check probe tools 151, 152 to contact the securing members 121 of the contacts 120 when the rear holder 130 is in the temporary locking position.
Thus, in cases where an electrical continuity check is performed on the electrical connector 101, as shown in FIG. 11A, the contacts 120 are arranged in the contact accommodating passageways 111 of the housing 110 and the rear holder 130 is arranged in the temporary locking position. The electrical continuity check probe tools 151, 152 are then disposed above and below the housing 110. As shown in FIG. 11B, the electrical continuity check probe tools 151, 152 are closed so that the electrical continuity check probe tools 151, 152 are attached to the housing 110. The contacts 153, 154 of the electric continuity check probe tools 151, 152 pass through the first and second openings 114, 115 of the housing 110 so that the contacts 153, 154 of the electric continuity check probe tools 151, 152 contact the securing members 121 of the contacts 120. Accordingly, the harness circuit is checked via the necessary detection circuit that is connected to the electrical continuity check probe tools 151, 152. After the electrical continuity check has been completed, the rear holder 130 is pushed with a specified force by a push-in jig 160 to the main locking position, as shown in FIG. 11C.
In the electrical continuity testing method shown in FIGS. 11A, 11B, and 11C, the contacts 153, 154 of the electrical continuity check probe tools 151, 152 are caused to contact the contacts 120 via the first and second openings 114, 115 formed in the top wall 112 and bottom wall 113 of the housing 110, respectively. Accordingly, there is no need to insert the electrical continuity check probe tools 151, 152 into an opening at a front of the housing 110.
Another example of an electrical continuity testing method is shown in FIG. 12 and is further illustrated in Japanese Patent Application Kokai No. 2001-110526. As shown in FIG. 12, electrical connector 201 has an insulating housing 210. A plurality of contact accommodating cavities 211 is formed in a single row inside the housing 210. A plurality of contacts 220 is arranged in the contact accommodating cavities 211. A locking arm 212 for securing the contacts 220 is disposed inside each of the contact accommodating cavities 211. An opening 213 that allows flexing of the corresponding locking arm 212 is formed beneath each of the locking arms 212 (below in FIG. 12). An insertion groove 214 is formed in a top wall of the housing 210 at a front end (left end in FIG. 12) of each of the contact accommodating cavities 211.
Each of the contacts 220 includes a substantially box-like receptacle 221 that is secured by the locking arm 212, and an electrical wire connecting member 222 that is connected by crimping to an electrical wire 240 of a wire harness (not shown). An elastic contact member 223 that makes elastic contact with a mating contact (not shown) is disposed inside the receptacle 221. A retainer 230 is inserted from a front side of the housing 210. The retainer 230 includes a retaining arm 231. The retaining arm 231 advances into the opening 213 formed beneath the locking arm 212 and prevents downward movement of the locking arm 212. A cut-out 232 communicates with the insertion groove 214 and is formed in a front edge of an upper surface of the retainer 230. An innermost surface of the cut-out 232 is formed as an inclined surface 233 with a downward slope.
During assembly of the electrical connector 201, the contacts 220 are inserted into the contact accommodating cavities 211 from the rear of the housing 210. As the contacts 220 are inserted, the contacts 220 cause the locking arms 212 to bend downward. When the contacts 220 are pushed in to a specified position, the locking arms 212 return to their original position and tentatively secure the contacts 220 in the housing 210. In this state, the upper surfaces of the front ends of the receptacles 221 of the contacts 220 are directly positioned beneath the insertion grooves 214. When insertion of all of the contacts 220 has been completed, the retainer 230 is fit over the front of the housing 210 and is pushed into the housing 210 until the retainer 230 is fully locked to the housing 210 in a main locking position. In the main locking position, the retaining arm 231 enters the opening 213 formed beneath the locking arms 212 and locks the contacts 220 in position.
Thus, in cases where an electrical continuity check is performed on the electrical connector 201 after assembly has been completed, an electrical continuity probe 250 is inserted from the front of the housing 210 at an inclination and with a tip end of the electrical continuity probe 250 oriented downward, as shown in FIG. 12. The electrical continuity probe 250 passes through the cut-out 232 of the retainer 230 and is inserted into the insertion groove 214 at an inclination until it is caused to contact the upper surface of the receptacle 221 of each of the contacts 220. As a result, an electrical continuity check is performed. Because the electrical continuity probe 250 is caused to contact the upper surface of the receptacle 221, which has a relatively high rigidity, deformation of the contacts 220 and, especially, deformation of the contact members 223, can be greatly suppressed during the electrical continuity check.
In the electrical continuity check method shown in FIGS. 11A, 11B and 11C, although an electrical continuity check can be performed when the rear holder 130 is in the temporary locking position, an electrical continuity check cannot be performed when the rear holder 130 is in the main locking position. Meanwhile, in the electrical continuity check method shown in FIG. 12, although an electrical continuity check can be performed when the retainer 230 is in the main locking position, no disclosure is made indicating that an electrical continuity check can be performed before the retainer 230 is fully locked to the housing 210. Because electrical continuity checks are typically performed by a harness maker, an automobile maker using the electrical connector, or the like, the tester is limited to performing the electrical continuity check when either the retainer is in a temporary locking position or a main locking position.